8,300 research outputs found
Qualitative Exploration of Ultrastructural Effects of Perfluorooctanoic Acid on Carp Gills: Mitochondria-Rich Cells as Candidate Biomarkers of Cytotoxicity
No full textPerfluorooctanoic acid (PFOA), a persistent per- and polyfluoroalkyl substance (PFAS), remains a global toxicological concern due to its ubiquity, bioaccumulation potential, and toxicity even at low concentrations. This study aimed to elucidate the ultrastructural effects of PFOA on the gills of Cyprinus carpio, a species of high ecological and trophic relevance. Gill samples from fish experimentally exposed to two PFOA concentrations (200 ng L−1 and 2 mg L−1), one of which was environmentally relevant, were examined by transmission electron microscopy. The results revealed cytotoxic changes primarily affecting mitochondria-rich (chloride) cells and, to a lesser extent, epithelial and mucous cells. The main alterations included mitochondrial degeneration, Golgi and endoplasmic reticulum stress, and autophagic activation, indicating a coordinated impairment of the endomembrane system. These findings suggest that PFOA induces a bioenergetic and proteo-synthetic imbalance compromising cellular homeostasis. Both direct cytotoxic and indirect endocrine-mediated mechanisms may contribute to the observed lesions. The pronounced sensitivity of mitochondria-rich cells supports their use as generalist biomarkers of PFOA exposure and effect. Within a One Health framework, these cells may also serve as translational models for elucidating conserved subcellular mechanisms of PFAS-induced cytotoxicity across vertebrates, with implications for environmental and human health risk assessment
Il viaggio africano di José Más
No full textQuesto lavoro ripercorre la storia della ricezione critica dell’opera di José Más (1885-1941) fino all’attuale risveglio d’interesse dovuto al suo ruolo pionieristico nella narrativa coloniale sulla Guinea Equatoriale, in particolare l’isola di Fernando Poo. Delinea quindi tutta la produzione d’ispirazione africana dell’autore, concentrandosi sul testo chiave, strutturato come viaggio, «En el país de los bubis» (1920), di cui analizza la materia autobiografica ed etnografica, i tratti stilistici e la strategia narrativa delle diverse parti, nonché la componente ideologica.
This article traces the critical reception of the work of José Más (1885-1941) and the current revival of interest due to its pioneering role in colonial writing on Equatorial Guinea, in particular the island of Fernando Poo. It outlines all African-inspired books of the author, focusing on the basic text, structured as a journey, ‘En el país de los bubis’ (1920), which analyzes the autobiographical and ethnographic material, the stylistic features and narrative strategy of its varied parts as well as the ideological component
The notions of creativity and meta-operativity in Emilio Garroni. Recent interpretations in the Italian aesthetic debate on technology
No full textThis contribution addresses Garroni’s notions of creativity and meta-operativity
on three levels, exploring recent interpretations and relationships with
contemporary aesthetic reflections about technology. Firstly, the paper discusses how
Garroni (1976, 1977, 1978) developed a reflection focused on aspects of creativity
and meta-operativity of human behaviour by drawing on Kant’s Third Critique. His
conception of creativity refers to a form of ‘productive imagination’, a meta-operative
process which allows us to deal with novelties by creating new rules and
developing a dynamic relationship between creativity and legality. Secondly, the
paper explores how the Italian philosopher (1986) foresaw the possibility of
establishing meaningful forms of relationships with reality by analyzing the
concept of experience, which allowed Aesthetic experience to be considered as a
way of renewing the agency and the heuristic potential of creativity, intended as
the main characteristic that defines the human behaviour. Thirdly, this
contribution explores how, by drawing on an under-standing of aesthetics intended
not as a ‘philosophy of art’ but, in a broader sense, as a ‘non-special philosophy’,
the author (2005) developed a comprehensive reflection on the concept of
perception that has led to the development of the concept of me-ta-operativity.
Finally, this contribution discusses how the latter was reinterpreted in
contemporary aesthetic reflections on perceptual aspects that define our relationship
with technological devices
Investigation of flashing induced instabilities in BWRS: Simulations and experiments
No full textFlashing induced instabilities in a BWR test-facility (CIRCUS) have been investigated. A steady-state model of the thermo-hydraulic behavior of a simplified natural circulation cooled BWR setup has been derived. An asymmetric power distribution in the core leads to asymmetric boifing boundaries in the core and small differences in flow-rate in the core-channels. However, the natural circulation is mainly driven by density differences between the riser section and the downcomer section, keeping the differences in flow-rate small. The time dependent flow-rate in the core-channels has been measured by means of LDA during unstable conditions ofthe CIRCUS facility, a steam-water simulator operating at 1.2 bar. Various asymmetric power distributions (leading to a difference in specific energy at the core exit up to 1 M J / k g ) have been studied under several core inlet temperatures, ranging from 98°C - 102°C. Increasing inlet temperature and total power leads to a destabilizing of CIRCUS at the particular points measured. Increasing asymmetry in power distribution leads to increasing flow-rate differences between the two core channels measured. The steady-state simulations overestimate the experiments, but the trends in flow-rate at increasing inlet temperature and total power are similar.Kramers Laboratorium voor Fysische TechnologieApplied Science
The Viral Author
No full textLa idea moderna de la "figura de autor" debe mucho, de manera irreversible, a los dos ensayos de Roland Barthes y Michel Foucault, "La muerte del autor" y "¿Qué es un autor?". Ellos proporcionan un marco útil para una investigación sobre la aparente ausencia del autor en el mundo del web, nos permite preguntarnos si la autoría es congruente con los nuevos medios de comunicación, y si algún modelo puede ser establecido por su presencia. Se argumenta que el autor es de hecho presente, pero con su presencia y modalidades de actividad desplazadas a la figura del usuario.The modern idea of the author-figure owes much, irreversibly, to the two essays of Roland Barthes and Michel Foucault, “The Death of the Author” and “What is an Author?”. They provide a useful framework for an investigation into the apparent absence of the author-figure in the online world, allow us to ask whether authorship is congruent with online media, and whether some model may be established for his presence. It is argued that the author is indeed present, but with his presence and modes of activities displaced, perhaps counter-intuitively, to the figure of the user
Criterios para la evaluación de la usabilidad de los recursos educativos virtuales: un análisis desde la alfabetización en información
No full textIntroducción. Para que el aprendizaje en entornos virtuales resulte realmente significativo, deben darse dos condiciones básicas: disponer de competencias relacionadas con la alfabetización en informaicón y, en especial, disponer de criterios adecuados para evaluar contenidos digitales.
Método. El principal objetivo de este trabajo es presentar un modelo de evaluación de la usabilidad de recursos educativos, desarrollado desde el punto de vista cognitivo del procesamiento de la información así como de las competencias esperadas en los estudiantes.
Análisis. El método utilizado para desarrollar el modelo ha sido la revisión de literatura y categorización de criterios de usabilidad relevantes.
Resultados. Un modelo de evaluación para contenidos educativos digitales habrá de considerar los siguientes criterios: Captación (relacionada con el mecanismo cognitivo de la atención), Fidelidad (relacionado con la percepción y Capacidad Alfabetizadora (ligada a la memoria).
Conclusions. Las Ciencias de la Documentación pueden desempeñar un papel relevante en distintas áreas: diseño de instrumentos adecuados para la gestión de contenidos educativos, implementación del constructivismo desde su perspectiva y para sus propios propósitos, adoptar competencias relacionadas con la alfabetización en información como objetivos didácticos en la formación profesional y el desarrollo de métodos adecuados para evluar competencias y contenidos.Publicad
CRISTINA MARTINELLI - NICOLA RUSSI, Wladyslaw Anders e Cosma Manera. Cammini per l'Umanesimo
No full textDjamila Ribeiro et la place des féminismes noirs au Brésil
No full textDjamila Ribeiro, journaliste, écrivaine et militante, est considérée comme une porte-parole du féminisme noir brésilien contemporain. Elle s’inscrit dans des mobilisations féministes croissantes qui, numériques ou non, suscitent l’intérêt des médias. Par son activité littéraire et éditoriale et sa présence sur les réseaux sociaux et dans les médias, l’auteure contribue à diffuser, voire à vulgariser, les savoirs noirs et postcoloniaux. La lecture de ses ouvrages, et notamment de Lugar de Fala (2017), essai traduit en France sous le titre La Place de la parole noire, révèle un ensemble de références intellectuelles qui ne sont pas circonscrites aux auteur·e·s brésilien·ne·s, mais incluent des textes fondateurs de la pensée féministe noire, états-unienne et globale. L’analyse des modèles théoriques de Djamila Ribeiro, ainsi que de la réception et de la circulation de ses ouvrages, permet de comprendre la posture intellectuelle et militante de cette figure marquante de la troisième vague féministe au Brésil.Journalist, writer and activist Djamila Ribeiro is considered a pivotal figure in contemporary black Brazilian feminism. She is part of a moment marked by a growing mobilization, virtual but also real, accompanied by a renewed media interest in feminist struggles in Brazil. Through her literary and editorial activity and her presence on social networks and media, the author contributes to disseminate, and even popularize, black and post-colonial knowledge. The analysis of her books, in particular Lugar de Fala (2017), an essay translated in France under the title La Place de la parole noire, reveals a set of intellectual references that are not limited to Brazilian authors, but include founding texts of black feminist thought in the United States and globally. The analysis of Djamila Ribeiro’s theoretical models, as well as of the reception and circulation of her works, allows us to understand the intellectual and militant posture of this prominent figure of the third feminist wave in Brazil
Intensidad laboral, encadenamientos intangibles y mercados. Las palancas del crecimiento económico de Baleares, 1800-2000
No full textThis article emphasises the importance in a regional economy such as the Balearic Islands of growth factors that are different from those conventionally considered in a large part of the literature on economics (existence of prime materials, location of energy sources, training of human capital, development of public capital). It asserts the idea that economic experience and informal learning processes, combined with social and economic agents’ capacity to adapt –which determines the plury-activity of the workforce–, led to Balearic leadership prior to the appearance of mass tourism. According to the author, this cannot be explained convincingly without the help of the dependent factors that created a solid basis in which connections with markets were crucial. Evolution in Balearic income is the common theme under study, on the basis of data available from the early nineteenth century to the dawn of the twenty-first century. This is therefore a recurrent, unimprovissed growth that should be taken into account, along with the models that are supported by the strength of investment and progress in cutting-edge innovation and technology.El artículo enfatiza la importancia de factores de crecimiento, en una economía regional como la de Baleares, distintos a los que suelen considerarse de manera convencional por buena parte de la literatura económica (existencia de materias primas, localización de fuentes energéticas, formación de capital humano, desarrollo del capital público). En concreto, se defiende que la experiencia económica y los procesos de aprendizaje no reglados, junto a la capacidad adaptativa de los agentes económicos y sociales –que determina la pluriactividad de la fuerza de trabajo–, condujeron a un liderazgo balear previo a la irrupción del turismo de masas. Éste, según el autor, no puede explicarse de forma convincente sin el concurso de esos encadenamientos, que generaron una base sólida en la que la conexión con los mercados resultó crucial. El hilo conductor que se adopta es la evolución de la renta balear, en función de los datos disponibles, desde principios del siglo XIX hasta los albores del XXI. Estamos, pues, ante un crecimiento recurrente, no improvisado, que debe ser tenido en cuenta junto a los modelos que descansan sobre la intensidad de la inversión y los avances de la innovación y de la tecnología puntera
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